A. Field of the invention
The invention relates to a method for introducing a weft thread in an air weaving machine. The invention also relates to an air weaving machine for applying a method of this type.
B. Related Technology
Air weaving machines in which compressed air is supplied to a number of blowers in order to transport a weft thread through a shed are known. In these machines, one or more main blowers and a number of auxiliary blowers are provided for the purpose of transporting a weft thread through a shed via an air-guiding passage. Weaving machines of this type include a supply device for supplying compressed air to blowers of this type. Supplying compressed air to a set of auxiliary blowers is effected, for example, by actuating a shut-off valve which is disposed between a buffer reservoir containing compressed air at a specific pressure and the set of auxiliary blowers for a certain period of time.
It is known from U.S. Pat. No. 3,705,608 to supply compressed air successively to the successive auxiliary blowers as the weft thread moves through the shed. It is known from U.S. Pat. No. 4,262,707 to select the period during which compressed air is supplied to the respective successive auxiliary blowers to be progressively longer in the direction of movement of the weft thread. This has the advantage that both a fast weft thread and a slow weft thread are sufficiently supported by compressed air coming from successive auxiliary blowers.
It is known from EP 0 554 222 A to provide at least one detector for detecting the arrival of the leading end of an inserted weft thread at a weft detector. Hereby the fluid injection from any of the auxiliary blowers is compensated as required in order to accelerate or to decelerate the weft thread such that the weft thread will timely arrive at the end of the shed opposite the main nozzles.